Noninvasive neural stimulation through audio

ABSTRACT

First data comprising a first range of audio frequencies is received. The first range of audio frequencies corresponds to a predetermined cochlear region of a listener. Second data comprising a second range of audio frequencies is also received. Third data comprising a first modulated range of audio frequencies is acquired. The third data is acquired by modulating the first range of audio frequencies according to a stimulation protocol that is configured to provide neural stimulation of a brain of the listener. The second data and the third data are arranged to generate an audio composition from the second data and the third data.

TECHNICAL FIELD

The present disclosure relates to neural stimulation, and in particular,noninvasive neural stimulation using audio.

BACKGROUND

For decades, neuroscientists have observed wave-like activity in thebrain called neural oscillations. Various aspects of these oscillationshave been related to attentional states. The ability to influenceattentional states, via noninvasive brain stimulation, would be greatlydesirable.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A and 1B are visual representations of entrainment, accordingexample embodiments.

FIG. 2 is a process flow for providing noninvasive neural stimulationusing audio, according to example embodiments.

FIG. 3 is a visual representation of audio filtering used in providingnoninvasive neural stimulation using audio, according to exampleembodiments.

FIG. 4 is an illustration of a software user interface configured togenerate a cochlear profile for use in noninvasive neural stimulationusing audio, according to example embodiments.

FIG. 5 is a visual representation of audio fidelity for use innoninvasive neural stimulation using audio, according to exampleembodiments.

FIG. 6 is an illustration of a software user interface configured togenerate a stimulation profile for use in noninvasive neural stimulationusing audio, according to example embodiments.

FIGS. 7A-C are visual representations of the alignment of a modulationsignal with the rhythmic elements of an audio element being modulatedaccording to phase and rate to provide noninvasive neural stimulationusing audio, according to example embodiments.

FIGS. 8A-C are visual representations of modulation depth for use innoninvasive neural stimulation using audio, according to exampleembodiments.

FIG. 9 is a graph comparing the Phase-Locking Value between a modulatedacoustic element and the output of an Electroencephalogram to thePhase-Locking Value between an unmodulated acoustic element and theoutput of an Electroencephalogram, according to example embodiments.

FIGS. 10A and 10B are illustrations of modulation waveforms used totarget specific areas of the brain for use in noninvasive neuralstimulation using audio, according to example embodiments.

FIG. 11 is an illustration of a software user interface used to generatestimulation waveforms that target specific areas of a brain fornoninvasive neural stimulation using audio, according to exampleembodiments.

FIG. 12 is functional diagram of an audio arranger used in noninvasiveneural stimulation using audio, according to example embodiments.

FIG. 13 is a flowchart illustrating a process flow for providing thenoninvasive neural stimulation using audio techniques, according toexample embodiments.

FIG. 14 is a functional diagram of an apparatus configured to providethe noninvasive neural stimulation using audio of the presentdisclosure, according to example embodiments.

DESCRIPTION OF EXAMPLE EMBODIMENTS

Overview

The present disclosure is directed to methods of neural stimulation withany audio. Example embodiments provide a neuroscience-informed way toselect for audio components which, when combined with modulated audiocomponents, create an audio arrangement which will stimulate the brainin a noninvasive way.

According to example embodiments of the present application, first datacomprising a first range of audio frequencies is received. The firstrange of audio frequencies corresponds to a predetermined cochlearregion of a listener. Second data comprising a second range of audiofrequencies is also received. Third data comprising a first modulatedrange of audio frequencies is acquired. The third data is acquired bymodulating the first range of audio frequencies according to astimulation protocol that is configured to provide neural stimulation ofa brain of the listener. The second data and the third data are arrangedto generate an audio composition from the second data and the thirddata.

Example Embodiments

Described herein are techniques that provide for non-invasive neuralstimulation of the brain. For example, the techniques of the presentapplication utilize modulation of audio elements (e.g., amplitudemodulation or volume modulation) to provide stimulus to stimulate thebrain. The concept behind this stimulation may be analogized to the wayin which unsynchronized metronomes arranged on a table will synchronizedue to constructive and destructive interference of the energytransferred between the metronomes via the platform on which they arearranged.

As illustrated in FIG. 1A, several metronomes 101 a-e beginunsynchronized at a time T1. Energy is transferred between metronomes102 a-e via table 102. The metronomes 101 a-e will reach a minimumenergy state, as illustrated in time T2, characterized in thesynchronization of the motion of metronomes 102 a-e. Thissynchronization is analogous to how periodic and temporally structuredsounds can synchronize and entrain the communication between neurons ofthe brain. External traveling waves (e.g., acoustic or audio waves) areconverted to neuro-electric signals (e.g., via the ear), which entraindesired neural excitations within the brain. In other words, periodicaudio may be used to entrain the attentional oscillatory cycles of thebrain. Such neural stimulation may be used to improve a user's focus,memory, meditation and sleep, among others.

FIG. 1B depicts a simplified illustration of synchronization of externalsignals and neural oscillations. External modulated sound 110 ispresented to the listener. The listener's existing neural oscillations111 become synchronized, or entrained to match the external signals asillustrated in entrained neural oscillations 112. Specifically, thephase of neural oscillations 111 has shifted to match that of externalsignal 110, as illustrated in entrained neural oscillations 112.

The present disclosure provides methods, apparatuses and computerexecutable media configured to provide such neural stimulation via audioelements. As used herein, “audio element” refers to a single audioinput, usually a single digital file, but also could be an audio feedfrom a live recording. As further explained below, the techniques may beparticularly effective when the audio stimulation is provided bypredetermined frequencies that are associated with known portions of thecochlea of the human ear. Furthermore, the techniques of the presentapplication provide for the selection of the waveforms configured totarget specific areas of the brain.

With reference now made to FIG. 2, depicted therein is a process flow200 according to the techniques described herein. The process flow 200is exemplary, and elements may be added or removed from process flow 200without deviating from the inventive concepts of the presentapplication. Process flow 200 is configured to generate a stimulationprotocol 260. As used herein, a “stimulation protocol” (such asstimulation protocol 260) is one or more values that determine how amodulator (such as modulator 250) modulates audio frequency data toinduce neural stimulation or entrainment. According to specific exampleembodiments, a stimulation protocol (such as stimulation protocol 260)may provide one or more of a modulation rate, phase, depth and/orwaveform for the modulation to be applied to audio frequency data thatis used to induce neural stimulation or entrainment. Modulation rate,phase, depth and waveform refer to four non-exclusive parameters used tocontrol any low frequency oscillator. Rate is the speed of theoscillation, often defined in hertz. Phase is the particular point inthe full cycle of modulation, often measured as an angle in degrees.Depth is the how large or small the modulation cycle is, in comparisonto what it is modulating. In amplitude modulation, it would be expressedas a linear percent of the whole volume available. Waveform expressesthe shape of the modulation cycle, such as a sine wave, a triangle waveor some other custom wave. Neural stimulation via such a stimulationprotocol may be used on conjunction with a cochlear profile to induceeffective stimulations in a user's brain.

The process flow 200 of FIG. 2 also provides for the generation of acochlear profile for use in noninvasive neural stimulation. A cochlearprofile refers to a list of frequency bands to be modulated generatedbased upon the portion of the human cochlea associated with theindicated frequency ranges. In other words, the cochlear profile refersa list of frequency bands to be modulated that correspond to one or morefrequencies within the human auditory range. Frequencies not specifiedwill be excluded from modulation. The process flow of FIG. 2 alsoillustrates the application of the stimulation protocol and the cochlearprofile to provide neural stimulation.

The process flow 200 begins with an audio element or elements 202. Anaudio element 202 may be embodied as a live recording, pre-composedmusic files, audio with no music at all, or a combination of elementsfrom all three. To achieve better brain stimulation, a wide spectrum ofsound may be used, as opposed to just a single tone or a several tones.Accordingly, audio elements 202 may be selected such that thecombination of audio elements have a large spectral audio profile—inother words, audio elements 202 are selected such that the combinationof the audio elements has many frequency components. For example, one ormore of audio elements 202 may be selected from music composed from manyinstruments with timbre that produces overtones all across the spectralprofile.

Furthermore, the audio elements 202 may be selected to ensure both alarge number of frequencies are being modulated, and also ensuring thatunmodulated frequency regions are also included so that a listener isnot disturbed by the modulations giving rise to the brain stimulations.For example, according to the techniques described herein, a band passfilter may be used to extract a frequency region, such as 400 Hz to 900Hz, from an audio element, while a band stop filter may be used togenerate a signal with all but the 400 Hz to 900 Hz frequency range.This extraction would result in one audio element file with only thisfrequency region and one audio element file without it. A “band passfilter” is a device or process that passes frequencies within a certainrange and rejects frequencies outside that range, while a “band stopfilter,” also called a notch filter, t-notch filter, band-eliminationfilter, and band-rejection filter, is a conventional audio process thatpasses most frequencies unaltered, but attenuates those in a range tovery low levels.

Illustrated in FIG. 3 is a simplified example of such a filterprocessing. Audio element 310 comprises two frequency components, afirst frequency component at a frequency of “X,” and a second frequencycomponent of “2X.” After passing through a band pass filter that filtersfrequency “X,” filtered audio element 315 is generated, comprising the“X” frequency component. After passing through a band notch filterconfigured to attenuate frequency “X,” filtered audio element 320 isgenerated, which comprises the “2X” frequency component. Audio element315 may be modulated to provide brain stimulation or entrainment, whileaudio element 320 would remain unmodulated. The two audio elements couldbe combined to create a cohesive experience not unlike the original savefor the additional modulations. Such an audio element may then be usedto provide neural stimulation and entrainment in such a way that alistener is not disturbed by the modulations giving rise to the brainstimulations. Real world audio elements may comprise a wide range offrequencies, and the band pass filter may extract a range of frequencyvalues, while the band stop filter would attenuate a range of frequencyvalues. The simplified audio elements of FIG. 3 were chosen toillustrate the effect of a filtering process as used in the presentexample embodiment with an easily visualized audio element. In fact, toachieve the best possible brain stimulation, a wide spectrum of soundmay be used, as opposed to just a single tone or a several tones.Furthermore, the stimulation may come from audio that has a largespectral audio profile—in other words, audio that has many frequencycomponents, like music with its many instruments and timbre thatproduces overtones all across the spectral profile, as will be describedin greater detail below.

Returning to FIG. 2, audio element 202 is provided to spectral analyzer210. Spectral analyzer 210 analyzes the frequency components of audioelements 202. “Spectral analysis” refers to sonographic representationsand mathematical analysis of sound spectra, or by mathematicallygenerated spectra. “Spectral range” or “spectral region” refers tospecific bands of frequencies within the spectra. As will be describedin greater detail below, spectral analyzer 210 may be used to determinehow the frequency components of audio element 202 are to be utilized toimplement the non-invasive neural stimulation techniques of the presentdisclosure.

Specifically, spectral analyzer 210 analyzes the frequency components ofeach audio element 202. If it is determined that one or more of audioelements 202 are composed of a large variety of frequency componentsacross the spectrum, the one or more audio elements 202 are sent to thefilter queue 211. As its name implies, the filter queue 211 is a queuefor audio filter 230. Because the stimulation protocol 260 may beapplied to a specific frequency or a relatively narrow range offrequencies, audio elements 202 that contain a large variety offrequency components undergo filtering in operation 230 to separatethese large varieties of frequency components. For example, audioelements that contain audio from a plurality of instruments may containaudio data with frequency components that cross the audible frequencyspectrum. Because the stimulation protocol 260 will only be applied to asubset of these frequencies, such audio elements are sent to audiofilter 230. In other words, the filtering of operation 230 selects afrequency range from an audio element for modulation.

If it is determined that one or more of audio elements 202 has a singlefrequency component, or multiple frequency components but centeredaround a narrow band, the one or more audio elements 202 are sent tounfiltered queue 212. In other words, if the audio element 260 covers asufficiently narrow frequency range, the stimulation protocol 260 may beapplied to the entire audio element, and therefore, no further filteringwould be required. Accordingly, such audio elements are sent to audioseparator 232. Audio separator 232 looks at the spectral data of anaudio input and pairs it with a cochlear profile to determine if theaudio input should be modulated or not.

Additionally, spectral data may be sent from spectral analyzer to one ormore of audio filter 230 and audio separator 232. This spectral data maybe used, for example, in conjunction with cochlear profile 231, todetermine which portions of the audio elements 202 are to be modulatedaccording to stimulation protocol 260.

Both audio filter 230 and audio separator 232 are configured to filteraudio elements for modulation (in the case of filter 230) or selectaudio elements for modulation (in the case of selector 232) based uponone or more cochlear profiles 231. Cochlear profile 231 providesinstructions to one or more of filters 230 and/or selector 232 basedupon the frequency sensitivity of the cochlear of the human ear.According to the present example embodiment, “cochlear profile” refersto a list of frequency bands to be modulated. Frequencies not specifiedwill be excluded from modulation.

With reference now made to FIG. 4, depicted therein is a visualrepresentation of the cochlea 400 of the human ear. The cochlea 400 isthe spiral cavity of the inner ear containing the organ of Corti, whichproduces nerve impulses in response to sound vibrations. Differentportions of cochlea 400 sense sounds at different frequencies due to theshape and rigidity of the cochlea 400 in the different regions. The baseof the cochlea 400, closest to the outer ear, is stiff and where higherfrequency sounds are transduced. The apex, or top, of the cochlea ismore flexible and transduces lower frequency sounds.

The cochlea, in addition to sensing different frequencies in differentregions, also has sensitivity that varies with the region of thecochlea. Each region has a number of cochlear filters that help thebrain decide what to pay attention to. Sensitive cochlear regions drawattention more than insensitive regions. For example, sound in thefrequency range of a human scream will draw our attention where the samesound, reduced in pitch to bass level, may be completely overlooked. Thedifference in reaction is largely due to the sensitivity of differentareas in the cochlea. Knowing how the cochlea and larger auditory systemdraw our attention enables neural stimulation to be incorporated intoaudio without disturbing the listener. Specifically, it has beendetermined that modulation targeting frequencies associated with theinsensitive regions of the cochlea will stimulate the brain withoutdisturbing the listener.

For example, by providing stimulation through the modulation offrequencies between 0 Hz-1500 Hz, the modulation may be less noticeableto the listener but the modulation may have a substantial stimulationeffect on the brain. Providing modulation at frequencies higher than the0 Hz-1500 Hz range may be avoided because the sensitivity of thecochlear regions increases dramatically for high frequencies. Similarly,the stimulation could be provided through modulation at frequenciesbetween 8 kHz and 20 kHz, as the sensitivity of the cochlea decrease atsuch higher frequencies.

As a counter example, sensitive areas of the cochlea may be targetedspecifically if the audio being modulated supports it without beingobtrusive. For example, there are relatively insensitive regions of thecochlea between 5 kHz and 6.5 kHz, and these frequencies may bemodulated in audio elements that lack significant audio components inthis range. For example, audio elements created using instruments thatdo not make great use of that range may provide stimulation throughmodulation of this range.

According to other examples, audio elements created with instrumentsthat make heavy use of a region within a usually insensitive band, suchas 900-1200 Hz, may be used for brain stimulation. These special casesmay be taken into account using spectral profiling, but generallyavoiding highly sensitive regions is a safe, effective way to highlystimulate the brain without disturbing the listener.

As illustrated in FIG. 4, region 410, a region sensitive to particularlyhigh frequency sounds, and region 440, a region sensitive toparticularly low frequency sounds, are generally less sensitive thanregion 430, a region sensitive to intermediate frequency sounds.

It has been determined that neural stimulation targeting insensitiveregions (i.e., stimulation protocols that modulate high and lowfrequency sounds) will stimulate the brain without disturbing thelistener. For example, stimulation protocols associated with theserelatively low sensitivity regions will achieve the entrainmentdescribed above with reference to FIG. 1. Yet, because the stimulationis implemented through frequencies to which the human ear is lesssensitive, the stimulation may not affect the listener's enjoyment of,for example, music that contains audio elements substantially within thesensitive region 430.

Further, it has been determined that modulation of both low and highfrequencies has a special effect on the brain. If both regions haveidentical modulation, the brain fuses the two regions into a singlevirtual source, increasing the fidelity of the stimulation waveform.Therefore, by avoiding sensitive cochlear regions while targeting bothhigh and low regions, the fidelity of the stimulation waveform may beincreased without disturbing the listener. For example, a piece of audiocould be modulated using frequencies between 0-1500 Hz and frequenciesbetween 8 kHz-20 kHz. The modulation of the two frequency regions may besubstantially identical in waveform, phase and rate. Such modulation maycreate increased waveform fidelity for both ranges of stimulation.

Fidelity of the waveform is analogous to the difference in resolution ofdigital images: a low resolution image has less pixels, and thus willnot be able to capture as much detail as a high resolution image withmore pixels. In the same way, high frequency carriers are able toincrease the fidelity of a modulation waveform. Depicted in FIG. 5 is anaudio analysis of amplitude modulation applied to a carrier of 100 Hz(210) where the waveform shape of the modulation is not clearlyrecreated when compared to a modulated carrier of 10,000 Hz (210), whichlooks smooth due to its higher fidelity.

The fidelity of the stimulation waveform may have a significant impacton the effectiveness of the neural stimulation provided by themodulation. Just as in audio synthesis, neural oscillations will reactdifferently depending on the waveform of the modulation.

Returning to FIG. 4, the visual representation of the cochlea 400 isimplemented through a software interface that may be used to selectcochlear regions to target for stimulation, in which cochlear regionsrepresent frequency bands across the spectrum of human hearing. Thesoftware interface of FIG. 4 would be used to create a cochlear profileto be used in filters and audio separators. For example, a user inputdevice 420 may be used to select portions of the cochlea 400 associatedwith the frequency ranges that the user determines should be stimulatedvia the stimulation protocol. According to the example of FIG. 4, theuser input device 420 has been used to select cochlear region 415associated with 7,000 Hz-8,500 Hz. Accordingly, the cochlear profile 231of FIG. 2, may instruct both the audio filter 230 and the audioseparator 332 to select 7,000 Hz-8,500 Hz as a frequency range toreceive modulation per the stimulation protocol. 260. The softwareinterface of FIG. 4 may also be used to add audio elements 406 to theproject, and assign audio elements 405 to the cochlear profile 407.

Returning to FIG. 2, each audio element in filter queue 211 may befiltered via audio filter 230, and based upon the frequency rangefiltered by audio filter 230, the frequency data may be sent tomodulator 250 for modulation according to stimulation protocol 260, orsent to mixer 251 for recombination with the modulated components forinclusion in a final audio element.

For example, audio filter 230 may receive instructions from the cochlearprofile 231 for each audio element being filtered. These instructionsmay indicate which frequency range within the audio element are to bemodulated, for example the frequencies corresponding to the lesssensitive portions of the human cochlea. In carrying out this operation,audio filter 230 may use one or more band passes to extract the chosenfrequency components for modulation 240. Accordingly to other exampleembodiments, band stop filters, equalizers, or other audio processingelements known to the skilled artisan may be used in conjunction with oras an alternative to the band pass filter to separate the contents offilter queue 211 into frequency components for modulation 240 andfrequency components that will not receive modulation 242.

The frequency components for modulation 240 are passed to modulator 250in accordance with the frequencies indicated in cochlear profiles 231.The remainder of the frequency components 242 are passed directly to themixer 251 where modulated and unmodulated frequency components arerecombined to form a single audio element 252. This process is done foreach audio element in the filter queue 211.

Similarly, audio separator 232 may receive instructions from thecochlear profile 231 selected for each audio element. Based upon theinstructions provided by cochlear profile 231, audio separator 232 mayseparate the audio elements contained in unfiltered queue 212 into audioelements to be modulated 243 and audio elements not to be modulated 244.By placing an audio element into audio elements to modulate 243, audioseparator 232 selects a frequency range comprising the entirety of theaudio element for modulation. Accordingly, the audio elements to bemodulated 243 are sent to modulator 250, while the audio elements not tobe modulated are sent to audio arranger 253, where these audio elementswill be arranged with audio elements that contain modulation to form afinal combined audio element.

As illustrated in FIG. 2, modulator 250 applies stimulation protocol 260to the frequency components for modulation 240 and the audio elements tobe modulated 243. The stimulation protocol 260 specifies the duration ofthe auditory stimulation, as well as the desired stimulation across thattimeframe. To control the stimulation, it continually instructsmodulator 250 as to the rate, depth, waveform and phase of themodulations.

Turning to FIG. 6, illustrated therein is an example of a stimulationprotocol according to the techniques described herein. In particular,FIG. 6 illustrates a software interface 600 that may be utilized tocreate a stimulation protocol to provide neural stimulation.Specifically, the stimulation protocol illustrated in FIG. 6 includescontrols for the rate of the stimulation 620, and the depth of thestimulation 640. According to the example of FIG. 6, these features ofthe stimulation protocol are defined as a function of time.

The rate of the stimulation 620 may be established such that themodulation provided by the stimulation protocol synchronizes amplitudemodulation of the audio elements being modulated to rhythms in theunderlying audio elements. The stimulation protocol may adjust themodulation phase to align with rhythmic acoustic events in the audio. Byaligning the modulation with the acoustic events in the audio elementsbeing modulated, the stimulation protocol may be generated to ensurethat the stimulation provided by the modulator is not interfered with bythe underlying audio elements being modulated, and vice versa, keeps thestimulating modulation from interfering with the underlying music.Rhythmic acoustic events such as drum beats in music, or waves in abeach recording, are perceived in the brain as a form of amplitudemodulation. If the modulation provided by the stimulation protocol isnot aligned with these rhythmic acoustic events of the audio elementsbeing modulated, the rhythmic acoustic events could interfere with thestimulation modulation. This misalignment would create interferencebetween the rhythmic elements of the audio elements and the amplitudemodulations meant to stimulate the brain. Accordingly, it may bebeneficial to synchronize the stimulation protocol modulation with therhythmic elements of the audio element being modulated.

Furthermore, synchronizing the stimulation protocol modulation with therhythmic elements of the audio element being modulated preventsdistortion of the audio by allowing the modulation cycle crest to alignwith the crest of notes or beats in music. For example, music at 120beats per minute equates to 2 beats a second, equivalent to 2 Hzmodulation. Quarter notes would align with 2 Hz modulation if the phaseis correct. 8th notes would align at 4 Hz, 32nd notes would align with16 Hz. If a stimulation protocol is being applied to music in an MP3which plays at 120 beats per minute (BPM), the stimulation protocolwould want to modulate the audio elements of the music file at 2 Hz.Specifically, “hertz” refers to a number of cycles per second, so 2 Hzcorresponds to 120 BPM, as a 120 BPM piece or music will have two beatsevery second. Similarly, the rate of modulation may be set as a multipleof BPM for the audio element.

Illustrated in FIGS. 7A-C are visual representations of modulations thatare not aligned with the beats of an audio element (FIG. 7A),modulations whose rate, but not phase, is aligned with the beats of anaudio element (FIG. 7B), and modulations whose rate and phase arealigned with the beats of an audio element (FIG. 7C).

The frequency of modulation signal 710 of FIG. 7A is not a multiple ofthe frequency of beats 715 a-d, and therefore, the maxima of signal 710cannot be aligned with beats 715 a-d. In other words, signal 710 has adifferent rate than the rhythmic components illustrated through beats715 a-d. Similarly, because modulation signal 710 begins at time T0 andthe rhythmic components of the audio element do not start until time T1,modulation signal 710 would be out of phase with beats 715 a-d even ifits rates were the same. The frequency of modulation signal 720 of FIG.7B is a multiple of the frequency of beats 725 a-d, but because themodulation signal 720 begins at time T0 and the rhythmic components ofthe audio element do not start until time T1, modulation signal 720 isout of phase with beats 725 a-d. The frequency of modulation signal 730of FIG. 7B is aligned with the frequency of beats 735 a-d, and thisalignment is accomplished by phase shifting the modulation signal 720such that modulation signal 730 begins at T1, instead of at time T0.

In order to ensure that the stimulation protocol aligns with therhythmic elements of the audio elements being modulated, the phases ofthe stimulation modulation and the rhythmic elements of the audioelement may be aligned. Returning to the example of the 120 BPM MP3file, applying 2 Hz modulation to the MP3 file may not align with therhythmic elements of the MP3 file if the phase of the stimulationmodulation is not aligned with MP3 file. For example, if the maxima ofthe stimulation modulation is not aligned with the drum beats in the MP3file, the drum beats would interfere with the stimulation modulation,and the stimulation protocol may cause audio distortion even through thestimulation modulation is being applied with a frequency that matchesthe rate of a 2 BPM audio element.

Such distortion may be introduced because, for example, MP3 encodingoften adds silence to the beginning of the encoded audio file.Accordingly, the encoded music would start later than beginning of theaudio file. If the encoded music begins 250 milliseconds after thebeginning of the encoded MP3 file, stimulation modulation that isapplied at 2 Hz starting at the very beginning of the MP3 file will be180° out of phase with the rhythmic components of the MP3 file. In orderto synchronize the modulations to the beats in the file, the phase ofthe modulation would have to be shifted by 180°. If the phase of themodulation is adjusted by 180°, the modulation cycle will synchronizewith the first beat of the encoded music.

In order to ensure that the stimulation modulation aligns with therhythmic elements of the audio elements being modulated, the audioelements are provided to a beat detector, an example of which isillustrated as beat detector 220 of FIG. 2. “Beat Detection” refers to aprocess of analyzing audio to determine the presence of rhythms andtheir parameters, such that one can align the rhythms of one piece ofaudio with the rhythms of another. Accordingly, beat detector 220detects rhythms in music or rhythmic auditory events in non-music audio.Beat detector 220 detects the phase and rate of the rhythms. Rhythmicinformation may already be known about audio element 202 through, forexample, metadata included in audio element 202. This rhythmicinformation may indicate the phase where the rhythm of the audio elementbegins (e.g., at a particular phase) or that the rhythmic element has adefined rhythm rate (e.g., defined in BPM of the audio element). Beatdetector 220 may be configured to read or interpret this data includedin audio element 202.

According to other example embodiments, rhythm detector 220 may beconfigured to analyze the content of audio elements to determineinformation such as the phase and BPM of audio element 202. For example,according to one specific example embodiment, five musical pieces wouldbe selected, and each musical piece would be a WAV file, six minuteslong. Beat detector 220 may determine that each of the musical pieceshas a BPM of 120. Beat detector 220 may further determine that eachmusical piece starts immediately, and therefore, each musical piece hasa starting phase of 0. According to other examples, beat detector 220may determine that each musical piece has a silent portion prior to thestart of the musical piece, such as the 250 millisecond delay providedby some MP3 encoding. Beat detector 220 may detect this delay, andconvert the time delay into a phase shift of the rhythmic elements ofthe music based upon the BPM of the musical piece. As illustrated inFIG. 2, the data determined by beat detector 220 is provided tostimulation protocol 260. This data may be used to ensure that themodulation provided by the stimulation protocol aligns with the rhythmicelements of the audio elements being modulated.

Returning to FIG. 6, the modulation rate 620 may be set to 16 Hz(corresponding to 32nd notes of a 120 BPM audio element) for the first 8minutes of the audio element, 8 Hz (corresponding to 16th notes of a 120BPM audio element) for the next 8 minutes, 4 Hz (corresponding to 8thnotes of a 120 BPM audio element) for the next 8 minutes and once againto 16 Hz for the final 6 minutes of the audio element. As illustrated inelement 630, the rate of the stimulation protocol may be dynamicallyadjusted to mate the rhythmic elements of the audio elements beingmodulated by the stimulation protocol based upon the data provided by,for example, beat detector 220 of FIG. 2. Similarly, the phase of themodulation may be dynamically mated to the rhythms in the audio viacheckbox 630. The rate 620 may also specified across the duration of thestimulation by moving points 610 a-d via user input.

As also illustrated in FIG. 6, the depth of the stimulation 640 may alsobe controlled. Modulation depth refers to the intensity of themodulation applied to the audio element. In other words, depth is thehow large or small the modulation cycle is in comparison to what it ismodulating. In amplitude modulation, depth would be expressed as alinear percent of the whole volume available.

The concept of modulation depth is illustrated in FIGS. 8A-C.Illustrated in FIG. 8A is an amplitude modulated signal 800. Value 810is the unmodulated peak to peak carrier amplitude, while value 820 isthe peak-to-peak audio amplitude after modulation. The percentage ofmodulation depth is the ratio of the peak-to-peak audio amplitude aftermodulation 820 to the peak to peak audio amplitude of the unmodulatedsignal. FIG. 8B illustrates a signal 830 with 50% modulation depth.According to this specific example embodiment, a modulation depth of 50%means that the modulation is causing 50% of the volume of the audioelement to rise and fall periodically throughout the audio element. FIG.8C illustrates a signal 840 with 100% modulation depth. According tothis specific example embodiment, a modulation depth of 100% means thatthe modulation is causing 100% of the volume of the audio element torise and fall periodically throughout the audio element.

Returning to FIG. 6, it has been demonstrated that high depth modulationproduces greater neural stimulation. High intensity neural stimulationof this type has the advantage of producing better behavioral results ina short period, such as 15 minutes, but can have disadvantages past thattime. In the same way that too much coffee can make one jittery, highintensity neural stimulation for too long can actually decreaseperformance. Therefore, it may be beneficial to moderate the depth ofmodulation across the stimulation timeline. For example, in a 30 minutestimulation session, one might modulate at a high depth of 70% for afirst portion of the audio element. However, at the 15 minute mark, themodulation depth may be gradually reduced such that the modulation depthis down to 50% by the end of the audio element. This would effectivelyhave the advantage of both high intensity stimulation and a “cool down”period where the user would be less stimulated and so maintain peakperformance. Such a stimulation session is illustrated in depth ofstimulation 640. As illustrated, the depth of modulation period 645increases from 25% to 75% to allow the listener some time to adjust tothe modulation. After this “ramp up” period, there is an extended periodwith 75% modulation depth to ensure a high level of neural stimulation.This period of high depth modulation may comprise a majority of theaudio piece to which modulation has been applied. Period 645 mayincrease the depth of the modulation over a period with a minimum length15 seconds. Additionally, modulation depth gradually decreases from 75%to 50% over the last 15 minutes of the audio element to preventoverstimulation. Accordingly to other example embodiment, this decreasein depth takes place of over a minimum length of time of one minute.Accordingly to still other example embodiments, the modulation depth maycontinually change from high to low and back again, with a minimum of 15seconds between high and low phases.

The depth 640 may also specified across the duration of the stimulationby moving points 612 a-d via user input. Finally, a save button 690 isprovided to save the protocol to an electronic medium.

Returning again to FIG. 2, as illustrated therein, stimulation protocol260 is based upon data provided by beat detector 220, and also waveformprotocol 259. Waveform protocol 259 may be used to effect neuraloscillatory overtones and/or to target specific brain regions byspecifying the waveform of the modulation pattern applied to the audioelements being modulated. Neural oscillations may react differentlydepending on the waveform of the modulation. Sine waveform modulationmay be used if stimulation is intended to target a single frequency ofneural oscillations. As a sine waveform has no overtones included in thewaveform, sine wave modulation waveforms may produce few overtones inthe brain. More complex waveforms may be used to produce neuraloscillatory overtones. “Overtones” or “harmonics” refer to resonantfrequencies above the fundamental frequency that are produced when thewaveform of an oscillator is anything other than a sine wave. An exampleof a waveform that contains overtones is illustrated in FIG. 3. Waveform310 includes a fundamental frequency “X” and an overtone or harmonic“2X.” Each of waveforms 315 and 320 contains just a sine waveform, andtherefore, just contains its respective fundamental frequency.

In music, overtones contribute to timbre—the way a piano and a guitar,playing the same fundamental frequency, will sound completely differentfrom one another. Brain imaging data has also shown that complexwaveforms delivered with waveforms that contain overtones result inbroader stimulation of neural oscillatory overtones far past the rangeof stimulation. Accordingly, “neural oscillatory overtones” refer toresonant frequencies above the fundamental frequency of stimulation.Like audio, or any data with a time-series, neural oscillations showharmonic and overtone frequencies when analyzing the spectrum and thefundamental frequency of stimulation.

With reference now made to FIG. 9, depicted therein are overtones ofneural stimulation modulated signal. Specifically, the phasesynchronization between an acoustic signal and the output of anElectroencephalogram (EEG) is illustrated. Phase-Locking Value (PLV) isa statistic that looks at the relationship between two signals, while anEEG measures brain activity. Accordingly, the PLV may be used toinvestigate task-induced changes in long range synchronization of neuralactivity. Specifically, the PLV statistic may be used as a proxy forconnectivity. If the two signals rise and fall together more than abaseline value, then there is more synchronization or loosely speaking,enhanced connectivity between these two signals. Accordingly, spikes inthe PLV 910 between EEG values and acoustic signals may be considered anindication of entrainment of the neural signals by the acoustic signalat the frequency where the spike arises. The analysis of FIG. 9 graphsthe PLV of an acoustic signal with an EEG signal. The solid line 910graphs the PLV for a modulated acoustic signal versus the EEG of thelistener, while the dashed line 920 graphs the PLV for an unmodulatedacoustic signal versus the EEG of the listener. There are peaks 925 atthe modulation rates used in the stimulation session 930: 8 Hz, 12 Hz,14 Hz and 16 Hz. Overtones, such as overtones 940 a-c, start to show upimmediately after region 930 and may continue throughout to much higherfrequency ranges.

Brain imaging data has shown that neural stimulation based upon complexwaveforms results in broader stimulation of neural oscillatory overtonesfar past the range of stimulation due to the presence of overtones, suchas the spikes 940 a-c of FIG. 9. Accordingly, waveform protocol 259 ofFIG. 2 may be configured to provide waveforms to stimulation protocol260 that are configured to provide stimulation past the range ofstimulation via overtones.

Waveform protocol 259 of FIG. 2 may also be configured to providewaveforms that target specific areas of the brain. Since the waveform isenhanced using the present invention, there is a unique opportunity totarget actual regions of the brain. Neural oscillatory waveforms differdramatically depending on the region of the brain being measured.Different regions of the brain exhibit different waveform shapes intheir neural oscillations. Even if two brain regions are firing at theexact same rate, the purpose of the oscillation may be very different,and the different purpose may be expressed through different waveforms.Matching the waveform of the stimulation to the brain region beingtargeted may enhance the effectiveness of neural stimulation and mayenhance the targeting of specific brain regions.

With reference now made to FIGS. 10A and 10B, depicted therein areexample embodiments of waveforms generated by waveform protocol 259 ofFIG. 2 configured to target and enhance neural stimulation for specificareas of the brain. Illustrated in FIG. 10A are the EEG output measuredfrom different regions on the brain. Alpha neural oscillations (whichrange from 8-12 Hz) are prevalent all through the brain, but servedifferent purposes in different areas. Even if two brain regions arefiring at the exact same rate, the purpose of the oscillation could bevery different. This difference in purpose of effect is often expressedthrough specific waveforms. 10 Hz oscillations measured from the frontalcortex 1010 look very different from the same oscillations rate takenfrom the motor cortex 1020. The motor cortex oscillations 1020 have an“M”-like shape to them among other features quite different from thefrontal cortex oscillations 1010 which are relatively smoother. By usingmodulation waveforms that generally mimic the shape of specific areas ofthe brain, neural stimulation of such specific areas of the brain may beenhanced. FIG. 10B illustrates examples of such modulation waveformsconfigured to target the frontal cortex 1030 and the motor cortex 1040.

Specifically, waveform 1030 is configured to enhance neural stimulationof the frontal cortex, and therefore, is shaped to mimic the shape offrontal cortex oscillations 1010. Accordingly, waveform 1030 is providedwith a relatively smooth shape, in this case, a shape similar to that ofa sine wave. Waveform 1040 is configured to enhance neural stimulationof the motor cortex, and therefore, is shaped to mimic the “M”-likeshape of motor cortex oscillations 1020.

If a user decides to generate a stimulation protocol to help easeanxiety by stimulating 10 Hz in the frontal regions of the brain, astimulation protocol may be generated to use the frontal waveform 1030at a rate of 10 Hz. The modulation could be applied to one or more audiofiles, and played for the user. This process would be much moreeffective than using a single modulation waveform for all purposes.

Waveform protocol 259 of FIG. 2 may be implemented through a softwareinterface like that illustrated in FIG. 11. FIG. 11 depicts an examplesoftware interface 1100 that may be used to generate or create awaveform protocol, which controls the waveform or waveforms used in thestimulation protocol 260 of FIG. 2. In the example of FIG. 11, awaveform is associated with a modulation rate. This means that when acertain modulation rate is being used it will automatically be used inconjunction with the associated modulation waveform. A user may enterthe desired modulation rate to be associated with the waveform protocolin the Modulation Rate textbox field 1110. Next, a depiction of the headand a typical EEG sensor array 1120 is presented to the user. Array 1120allows the user to select a sensor 1125 and retrieve a list of typicalneural oscillatory waveforms for that modulation rate (entered in textbox 1110) and brain region 1130. If the user selects the frontal cortex,included in list 1130 would be the relative smooth waveform 1030 of FIG.10. Similarly, if the user selects the motor cortex, included in list1130 would be the “M”-like shaped waveform 1040 of FIG. 10. The user maythen select the desired waveform 1140, and save the protocol viaselection button 1190. This waveform protocol may then be provided tostimulation protocol 260 of FIG. 2.

Returning to FIG. 2, once stimulation protocol 260 has been generated, aprotocol that may take into account the output of one or more of beatdetector 202 and waveform protocol 259, the protocol is provided tomodulator 250.

The stimulation protocol 260 specifies the duration of the auditorystimulation, as well as the desired stimulation across that timeframe.To control the stimulation, it continually instructs the modulator 250as to the rate, depth, waveform and phase of the modulations. Asdescribed above, the stimulation protocol 260 may instruct modulator 250based upon the output of beat detector 220 to ensure the rates aremultiples or factors of the BPM measured by rhythmic content in theaudio elements 202. As also described above, a modulation waveform maybe specified in the waveform protocol 259, and is used to effect neuraloscillatory overtones and/or to target specific brain regions, which isprovided to modulator 250 via stimulation protocol 260. Finally,modulation phase control of modulator 250 may be provided by stimulationprotocol 260 based upon beat detector 220 to ensure the phase ofmodulation matches the phase of rhythmic content in the audio elements202. Modulation depth control is used to manipulate the intensity of thestimulation.

The modulator 250 may use a low-frequency oscillator according to thestimulation protocol 260, which contains ongoing rate, phase, depth, andwaveform instruction. Low frequency oscillation (LFO) is a techniquewhere an additional oscillator, that operates at a lower frequency thatthe signal being modulated, modulates the audio signal, thus causing adifference to be heard in the signal without the actual introduction ofanother sound source. LFO is commonly used by electronic musicians toadd vibrato or various effects to a melody. In this case it is used tomodulate the amplitude, frequency, stereo panning or filters accordingto the stimulation protocol 260.

The modulator 250 is used to modulate frequency components 240 andunfiltered audio elements 243. Frequency components 240 are modulatedand then mixed with their counterpart unmodulated components 242 inmixer 251 to produce final filtered, modulated audio elements 252, whichare then sent to the audio arranger 253. Audio elements 243, on theother hand, are modulated in full, so they need not be remixed, and aretherefore sent directly to the audio arranger 253.

An “audio arranger” is a device or process that allows a user to definea number of audio components to fill an audio composition with musicwherever the score has no implicit notes. Accordingly, audio arranger253 arranges all audio content across the timeline of the stimulationprotocol 260. As illustrated in FIG. 2, stimulation protocol 260 sendsits timeframe to the audio arranger 253. In essence, audio arranger 253creates the final audio arrangement. Most importantly, audio arranger253 ensures that modulated content is always present, and is alwayscoupled with unmodulated content. Filtered, modulated audio elements 252automatically contain modulated and unmodulated content, but audioarranger 253 must still arrange them for maximum coverage across thetimeline. Modulated audio elements 254 and unmodulated audio elements244 must be arranged such that a modulated element is always paired withan unmodulated element, and that there are always at least two elementspresent throughout the timeline.

Illustrated in FIG. 12 is a logical flow chart of the computer functionsto be performed by audio arranger 253. As noted above, the job of theaudio arranger 253 is to ensure that modulated audio is always pairedwith unmodulated audio, as well as ensuring an even distribution ofavailable audio content. Audio elements, both modulated 254 andunmodulated 244, will be sent to the audio arranger 253, along withfiltered and modulated elements 252. Audio arranger 253 then distributesthe audio elements evenly across the span of the arrangement 1230. Audioarranger 253 also ensures that modulated elements 254 are always pairedwith unmodulated audio 254. For filtered, modulated audio elements 252,audio arranger 253 doesn't need to worry about pairing modulated andunmodulated content, since the filter already separated frequencycomponents such that each element already contains modulated andunmodulated components, so audio arranger 253 need only distribute theelements evenly 252. For example, audio arranger 253 may distribute theelements such that such that at least 50% of the stimulation timeline ofthe arranged audio file contains modulated frequency components.

Returning to FIG. 12, once arrangement is complete, the arranged audioelement is sent to the final mixdown 270 which provides a final mixdownand encodes the full audio onto an electronic medium. “Final mixdown”refers to the final output of a multi-track audio arrangement Amultitrack recording is anything with more than one individual track, ormore than one piece of audio layered on top of another, to be playedsimultaneously. The final output of multitrack audio is also known asthe mixdown.

With reference now made to FIG. 13, depicted therein is a flowchart 1300illustrating an exemplary process flow according to the techniquesdescribed herein. The process begins in operation 1305 where first datacomprising a first range of audio frequencies is received. The firstrange of frequencies corresponds to a predetermined cochlear region ofthe listener. In operation 1310, second data, comprising a second rangeof frequencies, is received. Examples of operations 1305 and 1310 mayinclude any combinations of operations corresponding to one or more ofoperations of 240, 242, 243 and 244 of FIG. 2. For example, the firstdata of operation 1305 may comprise frequency components to modulate 240of FIG. 2 that have been filtered out of an audio element by filter 230.According to other example embodiments, the first data of operation 1305may comprise audio elements to modulate 243 that have been separatedaudio separator 232 of FIG. 2. According to still other exampleembodiments, the first data in operation 1305 may comprises acombination of frequency components to modulate 240 and audio elementsto modulate 243 of FIG. 2. Example embodiments of the second data ofoperation 1310 may comprises frequency components not to modulate 242 ofFIG. 2, audio elements not to modulate 244 also of FIG. 2, or acombination thereof.

In operation 1310, third data is acquired that corresponds to a firstmodulated range of audio frequencies. The third data is acquired bymodulating the first range of audio frequencies according to astimulation protocol configured to provide neural stimulation of a brainof a listener. For example, operation 1315 may include the modulation bymodulator 250 of frequency components to modulate 240 and/or audioelements to modulate 243 according to stimulation protocol 260, asillustrated in FIG. 2.

In operation 1320, the second data and third data are arranged togenerate an audio composition from the second data and the third data.For example, operation 1320 may include the operations carried out bymixer 251 and/or audio arranger 253 of FIG. 2.

FIG. 14 illustrates a hardware block diagram of a computing device 1400that may perform the functions of any of the computing or controlentities referred to herein in connection with noninvasive neuralstimulation through audio. It should be appreciated that FIG. 14provides only an illustration of one embodiment and does not imply anylimitations with regard to the environments in which differentembodiments may be implemented. Many modifications to the depictedenvironment may be made.

As depicted, the device 1400 includes a bus 1412, which providescommunications between computer processor(s) 1414, memory 1416,persistent storage 1418, communications unit 1420, and input/output(I/O) interface(s) 1422. Bus 1412 can be implemented with anyarchitecture designed for passing data and/or control informationbetween processors (such as microprocessors, communications and networkprocessors, etc.), system memory, peripheral devices, and any otherhardware components within a system. For example, bus 1412 can beimplemented with one or more buses.

Memory 1416 and persistent storage 1418 are computer readable storagemedia. In the depicted embodiment, memory 1416 includes random accessmemory (RAM) 1424 and cache memory 1426. In general, memory 1416 caninclude any suitable volatile or non-volatile computer readable storagemedia. Instructions for the “Neural Stimulation Control Logic” may bestored in memory 1416 or memory 1418 for execution by processor(s) 1414.The Neural Stimulation Control Logic stored in memory 1416 or memory1418 may implement the noninvasive neural stimulation through audiotechniques of the present application.

One or more programs may be stored in persistent storage 1418 forexecution by one or more of the respective computer processors 1414 viaone or more memories of memory 1416. The persistent storage 1418 may bea magnetic hard disk drive, a solid state hard drive, a semiconductorstorage device, read-only memory (ROM), erasable programmable read-onlymemory (EPROM), flash memory, or any other computer readable storagemedia that is capable of storing program instructions or digitalinformation.

The media used by persistent storage 1418 may also be removable. Forexample, a removable hard drive may be used for persistent storage 1418.Other examples include optical and magnetic disks, thumb drives, andsmart cards that are inserted into a drive for transfer onto anothercomputer readable storage medium that is also part of persistent storage1418.

Communications unit 1420, in these examples, provides for communicationswith other data processing systems or devices. In these examples,communications unit 1420 includes one or more network interface cards.Communications unit 1420 may provide communications through the use ofeither or both physical and wireless communications links.

The above description is intended by way of example only. Although thetechniques are illustrated and described herein as embodied in one ormore specific examples, it is nevertheless not intended to be limited tothe details shown, since various modifications and structural changesmay be made within the scope and range of equivalents of the claims.

What is claimed is:
 1. A method comprising: receiving, by a computerprocessor, first data comprising a first range of audio frequencies,wherein the first range of audio frequencies corresponds to aninsensitive cochlear region of a listener; receiving, by the computerprocessor, second data comprising a second range of audio frequencies;acquiring, by the computer processor, third data comprising a firstmodulated range of audio frequencies by modulating the first range ofaudio frequencies according to a stimulation protocol, wherein thestimulation protocol is configured to provide neural stimulation of abrain of the listener, and wherein acquiring the third data comprisessynchronizing the modulating of the first range of audio frequencieswith rhythmic acoustic events in the first range of audio frequencies;and arranging, by the computer processor, the second data and the thirddata to generate an audio composition from the second data and the thirddata.
 2. The method of claim 1, wherein receiving the first data and thesecond data comprises filtering, by the computer processor, an audioelement into the first data comprising the first range of audiofrequencies and the second data comprising the second range of audiofrequencies; and wherein arranging the second data and the third data togenerate the audio composition comprises mixing, by the computerprocessor, the first modulated range of audio frequencies and the secondrange of audio frequencies.
 3. The method of claim 1, where receivingthe first data comprises receiving, by the computer processor, a firstaudio element and receiving the second data comprises receiving, by thecomputer processor, a second audio element.
 4. The method of claim 1,wherein the first data comprises data from one or more of a digitalaudio file, an analog audio file, or a live recording.
 5. The method ofclaim 1, wherein the first range of audio frequencies comprises a rangeof audio frequencies between 0 Hz and 1500 Hz, inclusive, a range ofaudio frequencies between 8 kHz and 20 kHz, inclusive, or a range ofaudio frequencies between 5 kHz and 6.5 kHz, inclusive.
 6. The method ofclaim 1, wherein the first range of audio frequencies comprises a highrange of audio frequencies and a low range of audio frequencies, andwherein the high range of audio frequencies and the low range of audiofrequencies are not continuous and are not overlapping.
 7. The method ofclaim 6, wherein acquiring the third data comprising the first modulatedrange of audio frequencies comprises modulating, by the computerprocessor, the high range of audio frequencies and the low range ofaudio frequencies in the same way using one or more of a same waveform,a same phase and/or a same rate.
 8. The method of claim 1, whereinacquiring the third data comprising the first modulated range of audiofrequencies comprises applying, by the computer processor, a modulationwaveform selected according to a region of the brain of the listener towhich the neural stimulation is to be targeted.
 9. The method of claim1, wherein modulating the first range of audio frequencies comprisesaltering, by the computer processor, the depth of modulation with time.10. The method of claim 1, wherein modulating the first range of audiofrequencies comprises applying, by the computer processor, amplitudemodulation to the first range of audio frequencies.
 11. An apparatuscomprising: a memory, and a processor, wherein the processor isconfigured to: receive and store in the memory first data comprising afirst range of audio frequencies, wherein the first range of audiofrequencies corresponds to an insensitive cochlear region of a listener;receive and store in the memory second data comprising a second range ofaudio frequencies; acquire third data comprising a first modulated rangeof audio frequencies by modulating the first range of audio frequenciesaccording to a stimulation protocol, wherein the stimulation protocol isconfigured to provide neural stimulation of a brain of the listener, andwherein the third data is acquired by synchronizing the modulating ofthe first range of audio frequencies with rhythmic acoustic events inthe first range of audio frequencies; and arrange the second data andthe third data to generate an audio composition from the second data andthe third data.
 12. The apparatus of claim 11, wherein the processor isconfigured to receive the first data and the second data by filtering anaudio element into the first data and the second data; and wherein theprocessor is configured to arrange the second data and the third data togenerate the audio composition by mixing the first modulated range ofaudio frequencies and the second range of audio frequencies.
 13. Theapparatus of claim 11, wherein the processor is configured to receivethe first data by receiving a first audio element; and wherein theprocessor is configured to receive the second data by receiving a secondaudio element.
 14. The apparatus of claim 11, wherein the processor isconfigured to acquire the third data by applying a modulation waveformselected according to a region of the brain of the listener to which theneural stimulation is to be targeted.
 15. A tangible, non-transitorycomputer readable media encoded with instructions, wherein theinstruction, when executed by a processor, are configured to: receivefirst data comprising a first range of audio frequencies, wherein thefirst range of audio frequencies corresponds to an insensitive cochlearregion of a listener; receive second data comprising a second range ofaudio frequencies; acquire third data comprising a first modulated rangeof audio frequencies by modulating the first range of audio frequenciesaccording to a stimulation protocol, wherein the stimulation protocol isconfigured to provide neural stimulation of a brain of the listener, andwherein the third data is acquired by applying a modulation waveformselected according to a region of the brain of the listener to which theneural stimulation is to be targeted; and arrange the second data andthe third data to generate an audio composition from the second data andthe third data.
 16. The tangible, non-transitory computer readable mediaof claim 15, wherein the instructions are further operable to receivethe first data and the second data by filtering an audio element intothe first data and the second data; and wherein the instructions arefurther operable to arrange the second data and the third data togenerate the audio composition by mixing the first modulated range ofaudio frequencies and the second range of audio frequencies.
 17. Thetangible, non-transitory computer readable media of claim 15, whereinthe instructions are further operable to receive the first data byreceiving a first audio element; and wherein the instructions arefurther operable to receive the second data by receiving a second audioelement.
 18. An apparatus comprising: a memory, and a processor, whereinthe processor is configured to: receive and store in the memory firstdata comprising a first range of audio frequencies, wherein the firstrange of audio frequencies corresponds to an insensitive cochlear regionof a listener; receive and store in the memory second data comprising asecond range of audio frequencies; acquire third data comprising a firstmodulated range of audio frequencies by modulating the first range ofaudio frequencies according to a stimulation protocol, wherein thestimulation protocol is configured to provide neural stimulation of abrain of the listener, and wherein the third data is acquired byapplying a modulation waveform selected according to a region of thebrain of the listener to which the neural stimulation is to be targeted;and arrange the second data and the third data to generate an audiocomposition from the second data and the third data.